Third-party Cookies are not created by the website being visited, but other domain. Let’s imagine a visitor is browsing forbes.com which has a YouTube video on one of its pages. In this case, YouTube will set a cookie which is then saved on a visitor’s computer. This cookie is classified as a third-party cookie, because it’s created by a different domain than forbes.com.

Third-party cookies are the fuel of online advertising. As advertisers add their tags to a page they can display ads, as well as track users and devices across the different sites they visit.

Since cookies can be used to store and retrieve information about users and their interactions with websites, they’ve been recognized as a threat to privacy. Because of the widespread use of cookies data is scattered across apps, websites and services. From the privacy perspective it’s difficult to say who does what with the data etc.

Find more details on third-party cookies on the Piwik PRO blog:

• First-party vs third-party cookies: why first-party is the way to go
• Google Chrome will wipe out third-party cookies. What’s next?
• What Intelligent Tracking Prevention (ITP) means for web analytics & marketing [Updated]
Check out our free Online Cookie Scanner